DE 1 905 561 U1 sets forth a valve arrangement of the generic type for controlling brake devices and auxiliary devices. A brake system for rail vehicles is disclosed, comprising a brake control valve, which is flange-mounted on a support module and controlled by the pressure in the main air line, and which is connected to an auxiliary brake reservoir and a brake cylinder. From the main air line a further secondary line leads to a further support module, which is connected by further piping to a pipe connection in the first aforementioned support module constantly subjected to the pressure in the auxiliary brake reservoir, and to a filling line. All auxiliary devices of the compressed air brake, in this case a monitoring device with stopcock, pressure-reducing valve and non-return valve for filling the auxiliary brake reservoir from the filling line, an electrical brake control device and the brake booster are flange-mounted on the further support module. The support module contains air ducts, which integrate the auxiliary devices, flange-mounted on the support module and arranged in conventional circuits, into the compressed air brake. The arrangement of the auxiliary devices on the support module allows them to be integrated, with only minor alterations, into an existing compressed air brake comprising the main air line, the first support module, the brake control valve, the auxiliary brake reservoir, the brake cylinder and corresponding connecting lines.